Mediation Analyses of Insight, Quality of Life, Depression, and Suicidality: Results From the FACE-SZ Cohort

Objective: The relationship between greater insight and increased risk of suicide in patients with schizophrenia is debated. The purpose of this study was to assess whether quality of life (QoL) and depression mediated the association between insight and suicidality.

Methods: Between March 2010 and December 2015, 527 community-dwelling adults with stable schizophrenia according to DSM-IV criteria were included in a multicenter cross-sectional study, the FondaMental Academic Centers of Expertise for Schizophrenia (FACE-SZ) Study. Structural equation modeling was used for mediation analyses among insight, QoL, depression, and suicidality, controlling for the global level of schizophrenic symptoms.

Results: The model provided a good fit for the data (χ23 = 1.4, P = .708, Tucker-Lewis index = 1, comparative fit index = 1, root mean square error of approximation = 0, standardized root mean square residual = 0.008) and explained 27% of the variance in suicidality. Poorer QoL and greater severity of depression mediated 68.4% of the positive association between insight and suicidality (full mediation). Poorer QoL mediated 48% of the positive effect of insight on depression (partial mediation). The severity of depression mediated 91.2% of the negative relationship between QoL and suicidality (full mediation).

Conclusions: Insight appears to be an indirect risk factor for suicide in patients with schizophrenia, with the link being mediated by poorer QoL and worse underlying depression, mainly by a sequential pathway but also by a less important parallel pathway.